Truck assembly for sliding doors



July 13, 1965 D, D, MoNlNcl-l 3,193,870

TRUCK ASSEMBLY FOR SLIDING DOORS Filed April 25, 1963 INV ENTOR.

United States Patent 3,193,870 TRUCK ASSEMBLY FR SLIDING DGORS Delmar D. McNinch, Rock Falls, Ill., assigner to Lawrence Brothers, Inc., Sterling, Ill., a corporation of Illinois Filed Apr. 25, 1963, Ser. No. 275,681 4 Claims. (Cl. 16-97) This invention relates generally to hardware for use in sliding door installations and especially to truck assemblies from which a sliding door may be suspended.

Silding doors, particularly those for interior use, are common suspended from a trolley or truck assembly that operates in a box track. The track is oridinarily attached to the top jamb of a door frame; and in the past, the truck wheels have been loosely assembled to their respective axles, reliance being had on the sidewalls of the box track to keep the wheels in place. Such an assembly of the wheels has created problems and inconveniences before final installation; and therefore, other truck assemblies have been devised for permanent but rotatable connection of the wheels to the axles, riveting over of the ends of the axles being the common practice. This latter procedure overcomes the handling problem and is relatively inexpensive, but the riveted ends of the axles tend to gouge the sidewalls of the box track or drag thereagainst impeding movement of the truck assembly.

Accordingly, an important object of the present invention is to provide a truck assembly in which the ends of the axles are arranged for anti-friction engagement with the sidewalls of the cooperating box track.

A more general object of the invention is to provide a new and improved truck assembly for use in a sliding door installation.

Another object of the invention is to provide a truck unit of the type described which is easily and quickly assembled.

Still another object of the invention is to provide a truck unit which is made up from a minimum number of component parts.

A further object of the invention is to provide a truck assembly which is economical to produce.

These and other objects and features of the invention will become more apparent upon a reading of the following descriptions.

A truck assembly in accord with the invention includes a yoke body having a transverse bore and an axle member having a central portion secured in the bore and having exposed end portions, each of which receives a wheel member in rotatable fashion. The truck assembly of the invention also includes a hub cap member mounted to each of the end portions of the axle member, each of the hub cap members having a disc portion for holding the corresponding wheel member in position on the axle. In order to present an anti-friction surface to the sidewalls of the receiving track and to the hub of the Cooperating wheel member, the disc portion of each of the hub cap members is fashioned from anti-friction material.

In order that the principles of the invention may be readily understood, a single embodiment thereof, but to which the application is not to be restricted, is shown in the accompanying drawing wherein:

FIG. 1 is a side elevational view of the top portion of a sliding door installation of the type including an overhead track, the track being cut away to reveal details of a truck assembly which is constructed in compliance with the invention, the door and its mounting plate being shown in cross-section to indicate their relationship;

FIG. 2 is a view taken substantially along the line 2-2 of FIG. 1;

FIG. 3 is an enlarged view taken substantially along the line 3-3 of FIG. l;

FIG. 4 is a view taken substantially along the line 4 4 of FIG. 2;

FIG. 5 is an enlarged, exploded perspective View of the truck assembly of FIG. l; and

FIG. 6 is a further enlarged, fragmentary perspective view of the axle used in the truck assembly of the invention.

Referring now in detail to the drawing, specically to FIGS. 1 and 2, a sliding door installation indicated generally by the numeral 1t) is seen to include an overhead box track unit 12, a hanger assembly 14, a door 16, and a top door bracket 18. The track unit 12 is adapted to be mounted to the top jamb of a door frame, not shown. In addition, the hanger assembly 14 includes a trolley or truck assembly 20 that is adapted for rollable movement in the box track unit 12. The hanger assembly 14 suspendedly supports the door 16, the bracket 13 being fastened to the top edge of the door by wood screws 22 and the hanger assembly 14 including a nut member 24 which is coupleable to the bracket 18 for this purpose. More specifically, the nut 24 includes an endless peripheral groove 26; and the central upwardly dellected section of the bracket 12 is fashioned with a laterally opening slot 28, the nut 24 receiving the edges of the slot 28 at the groove 26 for use in coupling the bracket 18 and its suspended door to the hanger assembly 14. The hanger assembly 14 also includes a drop bolt 30, the lower end of which is threaded for progressive engagement by the nut 24, The bottom portion of the nut 24 may be fashioned with a hexagonal section 32 if desired. When the hexagonal section 32 is provided on the nut 24, that section may be used in gripping the nut for adjusting the progressive engagement of the nut with the threaded portion of drop bolt 30. A locknut 34 may be employed in conjunction with the nut 24.

With reference to FIG. 4, the drop bolt 30 is fashioned with a cylindrical portion 36 intermediate its ends. A reduced diameter portion 38 overlies the cylindrical portion 36 to define a shoulder on which a main yoke or housing 4l) of the truck assembly 20 is positioned. The yoke 49 is perforated with a bore 42 which slidably and rotatably receives the reduced diameter portion 38 of the drop bolt 30. The drop bolt 30 is fashioned with a further reduced diameter portion 44 overlying the portion 3S; and in order to mount the yoke 40 to the drop bolt 30, a washer .46 is passed over the portion 44 to rest on the shoulder defined between the portions 38 and 44. Thereafter, the portion 44 is riveted over to dene a head 4S that serves to hold the washer 46 in place. If desired, a supplemental washer of bearing material may be disposed beneath the washer 45 in contact with the upper surface of the yoke 4l). In addition, the drop bolt 30 may be provided with an auxiliary head 50 between the cylindrical portion 36 and the lower threaded end portion, auxiliary head 50 being fashioned with a hexagonal section for ease in gripping the drop bolt.

Referring to FIG. 5, the main yoke or housing 40 of the truck assembly is seen to include a central hub 52 which is perforated with the aperture 42. In addition, the yoke 40 includes 1a pair of arms 54 which extend from the hub' 52 in diametric directions. The yoke 4h is advantageously fabricated in a die casting operation using a suitable alloy. Alternatively, the yoke 40 may be fabricated as a steel stamping or Vas an extrusion, and various metals may be employed. Each of the arms 54 is perforated with a transverse bore 56 in order to receive an axle member 58; and while various fabrications of the yoke 4l) have been described immediately hereinabove, the yoke 40 is to be so constructed that the sidewalls of the bores 56 are of yieldably deformable material.

In compliance with a feature of the invention, each of the axle members 58 includes a central portion @il of non-round cross-section. Each of the axle members 58 Y further includes cylindrical end portions 62 which :are adapted to be exposed laterally of the arms` 54 of the yoke itl for rotatably-receiving.wheel units 64. The end portions 620i the axle members are fabricated as tubularY tatably receiving the tubular end portions 62 of the corf f Vresponding axle member.

In further accord with the invention,'the axle members 58 are Atixedly secured inthe bores 56 of the yoke dit; and

for this purpose, the central portions 6i) of the axle members are fashioned with non-round. section, specifically hexagonal section in the embodiment shown. the central portion of each axle member isV somewhat Moreover, i

larger in diameter than the corresponding bore in the Y yoke; and at least the central portion of the axle memberV is made froma harder material than the yoke 4t). Thus,"

s be considered as being primarily illustrative.

disc portions 78 to the vertical sidewalls of the track unit 12 whereby to prevent either dragging or gouging of the sidewalls by the axles of thetruck assembly.

The specific example herein shown and described is to Various changes may occur to those skilled in the art; Vand such changes are to be understood as forming a part of this invention .insofar as they fall within the spirit and scope of theV `appended claims. Y Y

The invention is claimed as follows;

- l. A truck assembly for (use in a sliding door installation of the type including an overhead track, said truck assembly comprisingzf/a yoke body having means for attaching va sliding door thereto and having a transverse bore, the walls ofy saidrbore being of yieldably Vvdeformable material;v an axle member having exposed tubular ,end portions and af central portion situated in said bore in an interference t; a wheel'member rotatably mounted on'each lof said'end portions; and a hub .cap member mounted to each of said end portions, including a stern portion received in'said tubular end `portion Yand a disc the axle member may be assembled to theV yoke at a bore 56 in an interference rit, Vthe v,central portionV of the axle member deforming Y the sidewalls of the bore, cutting away and expanding the metal thereof to establish-an intimately fitted relationship. This is best seenV in FIG. 4. Y

Referring for the moment to FIG. 6, the axlemember 5S is Seen to be fashioned with a tapered portion 72 between the centralV portion dtrand one of the tubular end portions 62. This tapered portion ,72 acts to lead the non-round and Oversized central portion 6i) into the bore 56 in an easy manner. Returning to FlCkS, the opposite end of the central portion 60 is seen to lterminate in a fiat shoulder74 that is usedfto locate the axle member Ywith respect to the arm of the lyokein which it is assembled,l

the shoulder 74 being finally disposed coplanarly with a side face of the arm. Y Y

yIn cf'impliance'V with :another feature of the invention, each of the Wheel units 64 is held in placer'on an axle .member 58 by means of a hub .cap member 76; and as will be seen in FIG. 5, a hub cap`member 76 (comprises a disc portionV 78 and a stern portionS which extends! laterally from the disc portion '78 at the center thereof..

The hub cap member 76 is fashioned from an anti-friction t material, particularly a resinous antiffriction material such as nylon moldingresin'in order' that the disc portion 78 thereof may present an anti-friction surface to the side- Vwall of the track unit 12 and to the confronting surface, of the cooperating wheel unit 64. Advantageously, the stein portion at the outer endv of said stem portion for holding thef corresponding wheel memberin position on said axle member. l.

2. A truck assembly for use in a sliding door installation of the type including an overhead track, said truck assembly comprising a yoke body having means for attaching a slidingtdoory thereto and having a transverse bore, the walls of said' bore being of yieldably deformable material; an axle memberY having exposedj tubular end portions and a central portionsituated in said bore in an interference tit; -a wheel member rotatably mounted on each of. said end portions; and a hub cap member mounted to each of said end portions,.including aV stern portion received infa said Ytubular end Yportion and a disc portion at the outer end of said stemy portion forholding the corresponding'wheel member imposition on saidV axle member,Y said disc portion being of anti-friction materlal v Y hub of the cooperating lwheel member.'

portion 80 and the disc portion 7S are molded integrally; and the hub cap member 76V is adapted Vto be assembled Y to an axle member 58 by insertion of its stem portion 80 into the tubular end portion 62 of the axle member, the stem portion Si) being sized to establish an interference t.

Having thus described one constructionV of the truck assembly 20 and its relationship in the door installation 10, it is advantageous now to set forth the simple andl expedient manner in which the truck assembly,V Ztl is put together. First, vthe axle members 58 are inserted in the bores 56 of the yoke 40, the tapered portions 72 leading .the non-round central portions 60 into the corresponding bores 56." Next, the wheel units 64 are slipped onto the axle members. This assembly procedure is simple and convenient and incorporates aminimum number of individual operations.

Substantial production economies result. Moreover,Y as will be seen from an inspection of 3. A truck assembly for use inwa `slidingdoor installation of the type including van overhead track, said truck assembly comprising: afyoke body having'means'for attaching a sliding door thereto and having atransverse bore; an axle member having exposed `end portions and a central body situated in said bore; and a wheel member rotatably mounted on each of said end portions, one of said yoke body-andv said centralfbody being of relatively Vsoftrdeformable material and'V the other of said bodies being of Vrelatively khard material, the body of relatively deformable material being ygenerally conformed to the lshape of t-he Ybody of relatively hard material 'at-their region of mutual engagement whereby tok mount said axle member.' positively to yoke member.

vd. AV truck assembly accordingfto claim 3 wherein said transverse bore is originally of cylindrical shape and lwherein said central body is originallyk ofV non-round section.

v YReferences Cited bythe Examiner v UNITED STATES PATENTS 639,987 12/99 Tines V 16-98 1,192,966 8716 Willard 176-105 1,931,796 10/'33 Hoffman -v -..p 16-98 2,677,154 5/,54 Agle 16-98 2,917,771 12/59 Ylahrie 16-105 2,952,483 V9/60 VFleckrstein et al. V Y 287-52 '3,032,919 5/62 Amsler 46-17Y X FIG. 3, the hub cap members 76 present the anti-friction DONLEY I.' STOCKING" Primary Examnr 

1. A TRUCK ASSEMBLY FOR USE IN A SLIDING DOOR INSTALLATION OF THE TYPE INCLUDING AN OVERHEAD TRACK, SAID TRUCK ASSEMBLY COMPRISING: A YOKE BODY HAVING MEANS FOR ATTACHING A SLIDING DOOR THERETO AND HAVING A TRANSVERSE BORE, THE WALLS OF SAID BORE BEING OF YIELDABLY DEFORMABLE MATERIAL; AN AXLE MEMBER HAVING EXPOSED TUBULAR END PORTIONS AND A CENTRAL PORTION SITUATED IN SAID BORE IN AN INTERFERENCE FIT; A WHEEL MEMBER ROTATABLY MOUNTED ON EACH OF SAID END PORTIONS; AND A HUB CAP MEMBER MOUNTED TO EACH OF SAID END PORTIONS, INCLUDING A STEM PORTION RECEIVED IN SAID TUBULAR END PORTION AND A DISC PORTION AT THE OUTER END OF SAID STEM PORTION FOR HOLDING THE CORRESPONDING WHEEL MEMBER IN POSITION ON SAID AXLE MEMBER. 